1. Field of the Invention
The present invention relates to a detection device, especially to a short circuit detection device which identifies the location of a short circuit on a display panel.
2. Description of Related Art
Nowadays, the growing demand for computer, communication and consumer electronics products has ushered in an era termed as the 3C era. Conceivably, the market is filled with all kinds of information appliances such as mobile phones, personal digital assistants (PDAs), global positioning systems (GPSs), digital cameras and display apparatuses. In most information appliances, the flat panel display apparatus is used as the primary user interface.
Whereas almost all the conventional display apparatuses use the cathode ray tube as the primary user interface. With the advancement in the semiconductor fabricating techniques in recent years, the liquid crystal display apparatus is favored over the conventional cathode ray tube because it is lighter, thinner, more compact and consumes less power. Therefore, the liquid crystal display apparatus occupies a rather large share of the market.
FIG. 1 is a circuit diagram of a conventional pixel unit. Referring to FIG. 1, a conventional pixel unit 100 includes a scan electrode 102, a common voltage electrode 104, a data electrode 106 and a pixel electrode 108. Generally, the scan electrode 102 and the common voltage electrode 104 have different voltages. However, during the semiconductor fabricating process, if any particle (as shown by 110) falls on the scan electrode 102 and the common voltage electrode 104, a short circuit is caused between the two electrodes.
FIG. 2 illustrates the test result of a conventional pixel unit after an array test. Referring to FIG. 2, when a conventional pixel unit has a defect as shown in the pixel unit of FIG. 1, a short circuit is caused between the two electrodes. When the conventional pixel unit undergoes an array test or a cell test, it produces a horizontal-lined defect signal as shown by 210. However, the location of the defective pixel cannot be quickly and accurately identified according to this horizontal-lined defect signal 210. As a result, the testing time has to be prolonged and the production cost is increased correspondingly.